Hydrogen permeable protective coating for a catalytic surface

Abstract

A protective coating for a surface comprising a layer permeable to hydrogen, said coating being deposited on a catalyst layer; wherein the catalytic activity of the catalyst layer is preserved.

1. A protective coating for a surface comprising a layer permeable to hydrogen, said coating being deposited on a catalyst layer; wherein the catalytic activity of the catalyst layer is preserved;
 wherein the layer permeable to hydrogen comprises a carbon material that is amorphous. 
 
     
     
       2. The protective coating of  claim 1 , wherein the layer permeable to hydrogen is deposited using a vapor deposition process. 
     
     
       3. The protective coating of  claim 2 , wherein the vapor deposition process is a plasma enhanced chemical vapor deposition process. 
     
     
       4. The protective coating of  claim 1 , wherein the layer permeable to hydrogen is deposited at room temperature. 
     
     
       5. The protective coating of  claim 1 , wherein the catalyst layer is composed of platinum group metals. 
     
     
       6. The protective coating of  claim 1  wherein the catalyst layer is composed of platinum group metals, or their alloys. 
     
     
       7. The protective coating of  claim 1 , further comprising a chromogenic layer underlying said catalyst layer. 
     
     
       8. The protective coating of  claim 7 , further comprising a substrate layer underlying said chromogenic layer. 
     
     
       9. A sensor for sensing the presence of hydrogen gas in an environment, the sensor comprising:
 a protective layer permeable to hydrogen, wherein the protective layer comprises a amorphous carbon layer; 
 a catalyst layer deposited on said protective layer; 
 a chromogenic layer deposited on said catalyst layer; and 
 a substrate layer deposited on said chromogenic layer; 
 wherein the catalytic activity of the catalyst layer is preserved. 
 
     
     
       10. The sensor of  claim 9 , wherein the protective layer is deposited using a vapor deposition process. 
     
     
       11. The sensor of  claim 10 , wherein the vapor deposition process is a plasma enhanced chemical vapor deposition process. 
     
     
       12. The sensor of  claim 9 , wherein the protective layer is deposited at room temperature. 
     
     
       13. The sensor of  claim 9 , wherein the catalyst layer is constructed of platinum group metals. 
     
     
       14. The sensor of  claim 9 , wherein the catalyst layer is constructed of platinum group metals, or their alloys. 
     
     
       15. A protective coating for a surface, comprising a layer of amorphous carbon permeable to hydrogen, said amorphous carbon layer being deposited on a catalyst layer by a vapor deposition process, said catalyst overlying a chromogenic layer, said chromogenic layer overlying a substrate layer, wherein the catalytic activity of the catalyst is preserved. 
     
     
       16. The protective coating of  claim 15 , wherein the catalyst layer is an anode for a fuel cell. 
     
     
       17. The protective coating of  claim 15 , wherein the vapor deposition process comprises a plasma-enhanced chemical vapor deposition process. 
     
     
       18. The protective coating of  claim 17 , wherein the vapor deposition process uses ethylene as a processing gas. 
     
     
       19. A sensor for sensing the presence of gas in an environment, comprising:
 a protective layer permeable to the gas, wherein the protective layer comprises amorphous carbon; and 
 a catalyst layer underlying the protective layer, wherein the catalytic activity of the catalyst layer is preserved. 
 
     
     
       20. The sensor of  claim 19 , further comprising a chromogenic layer underlying the catalyst layer. 
     
     
       21. The sensor of  claim 19 , wherein the protective layer acts as a diffusion barrier to at least hydrocarbon, carbon monoxide, and sulfur-bearing gases. 
     
     
       22. The sensor of  claim 19 , wherein the protective layer is deposited directly upon the catalyst layer using vapor deposition. 
     
     
       23. The sensor of  claim 22 , wherein the vapor deposition is carried out at a temperature of about 30° C. 
     
     
       24. The sensor of  claim 19 , wherein the catalyst layer comprises a material selected from the group consisting of palladium, platinum, rhodium iridium, ruthenium, osmium, and alloys of these materials.